[meteorite-list] Patina

From: Gary K. Foote <gary_at_meteoritecentral.com>
Date: Fri May 12 10:25:10 2006
Message-ID: <446462B0.25502.AC7100_at_localhost>

Thanks Doug, for your thoughtful analysis. I had a piece of campo with an unusual shape
that came to me rusty and not looking like it was going to stop rusting. I took a wire
brush to it and removed the rust and now have a specimen that still shows flight details
and has nearly no rust. The only drawback is that I had to expose the high spots right
down to shiny metal to get the rust out of the low spots. I'm sure I lost some material,
but think it was minimal.

I've seen pallasites chopped up into medallions and such on ebay and think that kind of
manipulation is over the line, but I believe that what I have done makes the specimen
more 'enjoyable' to view. If you would like to see pics of before and after the links
are below;

Before: http://www.meteorite-dealers.com/images/campo-the-hand-600.jpg

After: http://www.meteorite-dealers.com/images/campohand-wirebrushed.jpg

Gary

On 12 May 2006 at 9:47, MexicoDoug_at_aol.com wrote:

> Gary F. writes:
>
> <<Which is best value wise? Original condition with dirt and natural patina
> or cleaned
> with patina left or cleaned and polished free of patina?>>
>
> Gary,
> Patina...if patina is an arrested natural finish, sounds awesome to me.
>
> There is "cleaned", and then there is "cleaned" just as there are stones and
> there are irons, and "scientific value" and "sentimental value" and "trade-in
> value". Never clean stones with solvents. Distilled water and reagent grade
> alcohol are in a questionable category here and questionable equates to not
> necessary. If the dirt comes off with your hands (and not a wire brush by
> wearing down the surface of the stone or iron, of course it is recommendable to not
> have such dirty meteorites in your collection - they will make everything
> dirty wherever you put them.) The one exception to the solvent rule is the
> ultimate form of cleaning - hacking off slices. To make a cut, you will need a
> friendly solvent - but you aren't asking about cutting.
>
> If you have a stable iron, the same applies. In economics there is a value
> to an option. Give the next guy a chance with the option "to clean or not to
> clean, and that is the question". If you choose to clean it, you will
> eliminate some of the demand because you have killed that option for those who want a
> natural meteorite. Less demand = less value both scientifically and one would expect
> monetarily. Same goes for whether you should cut a nice looking whole individual - don't.
>
> If you don't have a stable iron, you don't have much choice in the matter.
> Either you find an acceptable way to clean it or you will be left with a pile
> of junk. Pile of junk futures are not very scientifically or commercially
> valuable, though in this field there are suckers born every minute to keep such
> futures alive. The iron is rented anyway as it is a matter of time... So brush
> it with a stainless brush, boil it in parrafin, strip it, coat it in PU,
> pickle it a bit and then saponify it in caustic soda, vacuum pack it in beef jerky
> factory, sell it on ebay, whatever your heart enjoys. Have as much fun as I
> do when you are handed a sledgehammer at a carnival to smash a useless car, or
> as a shifty used car dealer who fixes up an old jalopy enough to have his
> hapless* customer drive it out the door...If it is a rare iron, though, better yet
> leave it alone and trade or give it to a museum so they can evaluate how to
> best preserve it for humanity, unless you realistically believe you can do a
> better job or have Bill Mason on your staff.
>
> *cool word, borrowed from a recent post
>
> Hope this helps. As you can see I am of the strict don't clean anything
> unless it is absolutely necessary belief. But then you have the irons that are
> borderline. For them, you want the natural naughty Squirrel Nutkin finish-and
> not sandblasted down to the patina and beyond- if an arrested natural nutshell
> exists. But if it doesn't (because one didn't develop, or because the soil
> was part of it and now the soil is removed), a good wire brushing may be in
> order though you will lose some weight, you will minimize the surface area for
> absorption of water and buildup of other catalytic corrosives...
>
> Saludos
Received on Fri 12 May 2006 10:25:52 AM PDT